package com.cy.interceptor;

import com.alibaba.csp.sentinel.adapter.spring.webmvc.callback.BlockExceptionHandler;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.csp.sentinel.slots.block.degrade.DegradeException;
import com.alibaba.csp.sentinel.slots.block.flow.FlowException;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;

@Component
public class ServiceBlockExceptionHandler implements BlockExceptionHandler {
    @Override
    public void handle(HttpServletRequest request,
                       HttpServletResponse response,
                       BlockException e) throws Exception {
        /*1、手动拼接json串*/
//        //设置响应数据的编码
//        response.setCharacterEncoding("utf-8");
//        //告诉浏览器要响应的内容格式，以及浏览器应该以什么编码进行显示
//        response.setContentType("application/json;charset=utf-8");
//        PrintWriter out = response.getWriter();
//        //向客户端输出一个json格式字符串 -- 手动拼接一个字符串
//        out.println("{\"code\":\"601\",\"msg\":\"访问频繁，稍后重试！\"}");
//        out.flush();
//    }
//}

        /*2、将对象转换为json串*/
        //设置响应数据的编码
        response.setCharacterEncoding("utf-8");
        //告诉客户端要响应的数据类型以及客户端以什么编码呈现数据
        response.setContentType("text/html;charset=utf-8");
        PrintWriter pw=response.getWriter();
        Map<String,Object> map=new HashMap<>();
        if(e instanceof DegradeException){//降级、熔断
            map.put("status",601);
            map.put("message", "服务被熔断了!");
        }else if(e instanceof FlowException){
            map.put("status",602);
            map.put("message", "服务被限流了!");
        }else{
            map.put("status",603);
            map.put("message",
                    "Blocked by Sentinel (flow limiting)");
        }
        //将map对象转换为json格式字符串
        String jsonStr=new ObjectMapper().writeValueAsString(map);
        pw.println(jsonStr);
        pw.flush();
    }
}
